There are many impossible-to-answer running questions.
“Which trainers should I buy?” is among the most common.
This is closely followed by “how long should running shoes last?”
I’m not going to attempt the first question (not here, anyway).
I’ll give the second one a go, though.
Rotation vs. single pair
There are two types of people. Those who use one pair of trainers at a time, and those who rotate through many pairs.
I’m in the “many pairs” camp. At any time, I have three or four that I wear regularly, with another two or three for “special occasions.” My wife reckons that I have “too many.” She’s probably right.
The “special” pairs are rarely worn. These include some trail shoes that live in the shed. A pair of racing flats I bought on a whim (and in the sale). And a well-worn pair of adidas Boston 6 that see me through the odd attempt at a quick parkrun.
The “regulars” are, by definition, used more often.
At the moment I have two favourites. Both are iterations of the Reebok Floatride Energy (v01, v02). Alongside these, my second pair of New Balance Zante v3 provide for speedwork. While a trusty old pair of Nike Pegasus 34’s add a reliable alternative for those long, lazy runs.
In fact, it was a recent plod in the Nike’s that inspired this post. Two and a half years old and with over 450 miles on the ‘clock’, they still feel fresh. How long will they last? I wondered. They seem to fair better than others I’ve owned. In fact, they feel like they’ll last forever. But that’s impossible. Isn’t it?
How long should running shoes last?
Ask on social media and someone will quote “about 500 miles” at you. I don’t know where that figure came from. I expect marketing people were involved.
The truth is, there isn’t a definitive answer. There are too many things to take into account.
Then there are the trainers themselves. The materials used in the upper, midsole and outer sole. How well they fit your feet. Whether you rotate various trainers or stick to a single pair.
Even the brand’s development cycle can play a part. Sometimes, with all the best intentions, a manufacturer can miss the mark. They tweak, adapt and evolve to add bounce, reduce weight and improve fit. These changes come with compromise. All too often, it’s durability that takes the hit.
Individual form, physicality and training patterns need posts of their own. For now, I’ll stick to talking about the trainers.
Why do we need to change them?
“The human foot is a masterpiece of engineering and a work of art”Leonardo Da Vinci
Manufacturers spend huge sums developing super high-tech foam for the mid sole. They lay hard-wearing, lightweight rubber compounds along the base. And they craft highly engineered materials, formed into single-piece, seam-free uppers. Then they stitch the whole ensemble together with as little extra weight as possible.
All that, for us to stick them on stinking feet and pound pavements for mile after mile, doing our best to ruin them. And, like it or not, we will ruin them. It’s true. Your expensive trainers will wear out and, as they do, you’re more likely to suffer injuries.
To explain that, requires a little wander through our past.
There are some interesting studies around human evolution and how we developed into perfect running machines. That development takes in our ability to sweat, coupled with our physiology.
With evidence of our ancestors “jogging” almost 2 million years ago, it seems we’ve been running for quite a while. By contrast, it wasn’t until the 1970s that anyone thought to stick a slab of foam under our feet.
As Da Vinci said, “The human foot is a masterpiece of engineering…”. Perfectly suited for its purpose, it was never intended (for want of a better word), to be supported by foam.
But, for the majority of runners, that’s now the norm, especially among those that run on pavements (something else that’s relatively recent).
There’s a school of thought that we should remove shoes from running altogether. Indeed, Nike’s first “running shoes” used a miniscule strip of rubber, cast in a waffle iron. The idea that we need cushioned foam was born in a marketing department and traded on fear of injury. Ironic really that the more cushioning we add, the more likely we are to suffer injury.
That slab of bouncy foam is bad for our bodies in several ways. It prevents our natural “proprioception”. In some cases, they stuff extra foam up into the arch, which weakens the strongest part of the foot. And they allow us to run lazily and heavily, sometimes striking heel first.
I don’t necessarily agree that we should abandon modern running shoes and head out bare foot. Dog plops, broken glass and weakened feet are reasons enough to keep our toes under wraps. However, the more accustomed we are to that pillowy softness under our feet, the less able we are to change our gait as that softness hardens.
This means, when the bounce runs out, our bodies take the strain.
How do they wear out?
I’m a big fan of www.solereview.com. Their reviews are the most thorough, insightful and well-written that I’ve come across. It’s because of them that I’m reluctant to start reviewing trainers myself.
One great feature of their reviews is the estimated lifespan. They offer realistic upper and lower estimations for lifespan. And they explain why that lifespan might be either good or bad. Check them out before you invest in your next pair of trainers.
As for how our shoes wear out – there are several points to consider.
These days, the majority of running shoes use an engineered mesh upper. Often printed in a single piece to reduce stitching and seams. Structural overlays prevent floppiness and add reflectivity. They’re lightweight and flexible. And they’re often produced in a dazzling array of ludicrous colours.
As an alternative, some trainers use a knitted upper. Here, rather than relying on overlays to add structure, the knit itself does the hard work. Lighter, breathable and flexible, they’re also more durable than their meshy counterparts. What’s not to like? Well, the cost for a start. Something has to give. In this case, it’s your wallet.
With both mesh and knit, the technology is sound. Depending on the fit, your running style and how much you abuse them, the uppers should outlast the soles. Although, if they’re too tight and your nails too gnarly, it’s possible to poke a toe through, over time.
Another upper part that’s prone to fail is inside the heel. My On Clouds, the most expensive trainers I’ve owned (and definitely one of my favourites), failed here too quickly.
It’s debateable whether this affected my “performance”. But it was uncomfortable, and eventually caused blisters. Neither of those are welcome when running.
Many would argue that the midsole is the most important part of any running shoe. That sometimes air pocketed, carbon plated, squishy bit that does the heavy lifting. And they might be right. But keeping that bit protected over countless miles is also important. Doing so while adding grip and without a load of extra weight is a big challenge.
Many shoes have a slither of a hard rubber compound covering the midsole. Sometimes small “nodes” offer traction and an extra barrier against wear and tear. More often than not, this slip of rubber covers the entire foot. It’s a popular option and, arguably, the most durable.
Others use a layer of blown (air injected) rubber. It’s lighter and more flexible than the harder compound but it lacks the durability. It’s usually found in the forefoot, with a harder rubber making up the back end of the shoe.
Whichever rubber is used, the outer takes the most punishment and will show the first signs of wear. Again, running style plays a part. My trainers often lose rubber from the big toe area, while the heal stays almost virginal. Some people find the heal takes a battering while others might notice erosion down one or other side. If you suffer recurring injury, look at the erosion patterns on your shoes. It could be a sign that your form needs some attention.
This bit should sit in the middle of the list. Physically, as the name suggests, the midsole sits between upper and outer. But some would argue that it’s the most important part. So, much like the meat in my Sunday roast, I’m saving it for the end.
Midsole technology is where most manufacturer money goes. Polyurethane, Ethylene Vinyl Acetate, carbon plates and air bubbles. In the quest for cushioned, lightweight, responsive shoes, brands work hard for our hard-earned cash. And they do it well – a runner and his money are easily parted.
Personal differences aside, durability depends on a few things. The materials used, the density of the sole and how those two elements come together. You can throw in outer sole durability as well – if you go through your outer sole, your midsole is doomed!
As I said above – there are arguments for going barefoot. Failing that, there’s a case for reduced cushioning. At the moment, though, the trend is for thicker, more cushioned soles. As a result, we must be conscious of the likelihood of injury as our shoes lose bounce.
The consequence of midsole wear on the wearer varies according to both the shoe and its owner. Simply, the more cushioned the shoe, the more likely the wearer will depend on the cushioning. Conversely, the more minimalist the shoe, the lighter its wearer will run. You won’t find a barefoot running landing heavily on their heels. Not for long, anyway.
There are certain signs that your midsoles are at the end of their life. Creases along the sides and increased firmness under foot, for example. Also, if they become sluggish and unresponsive. Or you often pick up injuries while wearing them. Each of these could mean they’re ready for gardening duties.
It’s important to keep in mind how far your shoes have taken you. And to note any change in how they feel. Especially if you like a thick bit of foam under foot – you might rely on it more than you realise.
So, how long should running shoes last?
The simple answer – probably longer than you think, but not as long as you’d like.
If you’re as dull as I am, you’ll keep track of the miles covered in each shoe. That way, you too can be surprised when a favourite pair still feels great, even though they’ve almost reached their 500 mile “limit”.